Method for the multi-core deburring of wires and associate

ABSTRACT

The invention relates to a method for the multi-core deburring of wires, preferably wires ( 1 ) separated from a wire strip comprising a plurality of wire strips which are arranged parallel to each other, in particular for producing round wires and shaped wires. The wires ( 1 ) are, after passing through a pair of separating rollers ( 3 ), separated by a separating roller unit ( 4 ) according to even-numbered and odd-numbered wires, such that two stands of mutually distanced wires ( 1 ) are formed. Both of the wire strands ( 1 ) then traverse according to an adjustable tensile stress, respectively a deburring station provided with deburring blades. The tensile stress is selected in such a manner that after taking into account the notch angle and the blade angle of the deburring blades, the wires ( 1 ) undergo an automatic, central alignment ensuring chips are removed in a uniform manner on both sides of said wires ( 1 ). Subsequently, the wires ( 1 ) are brought together in a traction unit ( 6 ) comprising rollers to again form a common strand of wires ( 1 ). The invention also relates to a corresponding device.

The invention relates to a method for simultaneously deburring amultiplicity wire conductors, preferably a plurality of wire conductorsthat are separated from a wire conductor ribbon and are parallel to eachother, in particular for producing round and shaped wires, wherein asheet metal ribbon is first pregrooved on one or both opposite faces soas to create the wire conductors of the wire conductor ribbon, afterwhich grooving the wire conductors still connected by webs undergo aflexing process so as to then transform the webs into thin frangiblewebs that are easily separable from each other and form smooth andnearly burr-free edges when detached, each web undergoing repeatedbending deformation about its longitudinal axis in such a way thatincipient cracks forming the frangible web are created by fatiguefailure at the webs, wherein the frangible web can also be openedlocally. Production of this type of wire conductor ribbon is describedin WO 2008/135002 [US 2010/0129678].

In the conventional production of round wire, a wire conductor isessentially cast, extruded or hot-rolled, and subsequently stripped,scraped, pickled, etc., after which this wire conductor is then drawnuntil reaching the desired final size.

Based on the above description, individual wire conductors, for exampleof very small size such as less than 1 mm in diameter, can be extractedfrom a wire conductor ribbon for further processing in a conventionalwire production process. The entire preproduction process is theneffected by rolling, which generally is more cost-effective; however, itis also possible when producing fine and ultrafine wire, for example fora plurality of wire conductors to be extracted simultaneously from thewire conductor ribbon produced from a metal sheet, where what is left isonly a running-out starting-material ring that has been produced inpreproduction exclusively by rolling. To ensure quality, it isadvantageous for the edges together with frangible webs and frangibleweb remnants to be extracted from the wire conductors.

The object of this invention is therefore to provide a method fordeburring wire conductors that have been created by the process ofseparating a wire conductor ribbon formed out of a metal sheet. Thisobject is achieved according to the invention by an approach in whichthe wire conductors, after passing through a separating roller pair, arespread apart according to even-numbered and odd-numbered wire conductorsby a spreading roller unit such that two arrays of mutually spaced wireconductors are created, wherein furthermore the two arrays of wireconductors pass under adjustable draw tension through respectivedeburring stations provided with respective deburring cutters, where thedraw tension is selected such that an automatic central alignment, andthus a two-sided uniform removal of chips, is effected on the wireconductors due to the action of the groove-flank angle and of theadjusted angle of the deburring cutters, and wherein finally the wireconductors are reunited into a common group of wire conductors byrollers of a drawing unit, thereby achieving uniform drawing conditionsfor all wire conductors and transferring the wires on for furtherprocessing.

The advantage achieved by the invention essentially consists in the factthat, due to the separation of the initially closely adjacent wireconductors into two arrays, a space of the width of one wire conductoris now created between the wire conductors, thereby allowing deburringto be effected laterally on the originally present frangible webs. Thesubsequent reuniting of the two arrays in the drawing unit enables thethen deburred wire conductors to be transferred on for furtherprocessing. If another means is found to ensure that the same draw forceis applied to both arrays—by means of appropriately controlled electricmotors, for example—then the subsequent reuniting of the two arrays canbe eliminated. In other words, both arrays can also be moved along forseparate further processing in the event this is desirable in terms ofthe process. If the selected spacing between the spreading rollers andthe drawing unit is sufficiently large and the deburring station is thenpositioned centrally between these, the individual wire conductors willautomatically align themselves centrally relative to the deburringcutters of the deburring device, since the cutting widths of the chipson both sides of the wire conductors will automatically adjust to be ofequal width due to the pitches of the grooves (for which a groove-flankangle ranging between 45 and 90′ is advantageous). This obviates theneed for horizontally guiding the wire conductors upstream of thedeburring devices. The cutting pressure is sufficient to appropriatelyset the wire conductors centrally. As a result, the surfaces of theseparating surfaces are completely removed reliably bilaterally on bothsides of the respective wire conductors—a factor which is necessary toensure quality.

In a preferred embodiment of the invention, the wire conductors pass inthe deburring station through a comb-like deburring device provided withtines that form deburring cutters.

It is furthermore critical that the wire conductors in the deburringstation be transported under tension, where the drawing unit providedwith guide grooves generates the draw force that is also required toadvance the wire conductors, while the separating roller pair as well asthe spreading roller unit provided with guide grooves generate a brakingforce.

Appropriately coordinating these units with each other enables thespecific advantageous tension to be effected. It can also beadvantageous in this regard if the tension in the wire conductors can becontrolled in a continuously variable fashion between the two units.

It has furthermore been found advantageous within the scope of theinvention for the wire conductors not to be subject to any horizontallyrestricted guidance so as to provide a uniform, two-sided deburringoperation in the region upstream and downstream of the deburringstation. This enables the wire conductors to be horizontally alignedcentrally by the two cutters engaging on the left and the right so as toachieve a uniform two-sided deburring. The effect of self-alignment bythe wire conductors in the deburring device is most efficient if thewidth-to-thickness ratio is not significantly greater than 1:1. Anotheraspect of the invention is that the wire conductors are guided upstreamof the deburring devices only under light contact pressure acrossrespective guide rollers; that is, this pressure is applied only verygently. This attenuates vibration and furthermore ensures that the wireconductors get twisted before passing through the deburring device,while the possibility of a horizontally centered alignment still exists.

The feeding of a new wire conductor ribbon into the deburring station islaborious in that the start of the wire conductor ribbon into theupstream separating rollers is not separated, and the wire conductorribbon is guided and threaded up to the drawing unit when the spreadingroller have not been mounted. During subsequent configuration, theseparating rollers are activated and the wire conductor ribbon isseparated until the separated wire conductors have reached the drawingunit. Then a sufficient length of wire conductor is generated betweenthe separating rollers and the drawing unit to allow the spreadingrollers to be mounted. At the same time, the array of wire conductors isdivided up so that, for example every second wire conductor number isguided over the top spreading roller, while the other wire conductorspass over the bottom spreading roller and are fitted there into therespective guide grooves. The wire conductors are then placed undertension and the deburring devices are installed. In order to allow thisto be done as rarely as possible, it is useful to employ long wireconductor ribbons, although the length of these cannot be unlimited. Forthis reason, the invention proposes an approach whereby the wireconductor ribbon passes through a welding station before entering theseparating roller pair, in which station a new wire conductor ribbon isbutt-welded on when the end of a wire conductor ribbon is reached suchthat the individual wire conductors are flush to one another. Thisapproach essentially allows the process in principle to be carried outwith an “endless” wire conductor ribbon, as long at least as wireconductor ribbons of identical dimensions and geometry are being worked.Specifically, it has been found that the welded seam does not negativelyaffect the separation of the individual wire conductors from each otherat the frangible web, and this is particularly true according to anotherproposal of the invention whereby the welding bead formed on the weldingseam is ground flat on both sides of the wire conductor ribbon, and thewelding bead at the grooves is also almost completely removed by anappropriately shaped tool by simultaneously grinding the top and bottomface of the wire ribbon.

In terms of an apparatus, the object of the invention is achieved by adeburring station for a wire conductor ribbon that is formed from ametal sheet pregrooved on one or both faces and in which wire conductorsstill connected by webs after grooving undergo a flexing process so asto transform the webs into thin frangible webs that are easily separablefrom each other, and form smooth and nearly burr-free edges whendetached, whereby, after undergoing repeated bending deformation abouttheir longitudinal axis, incipient cracks forming the frangible webs arecreated by fatigue failure at the webs, wherein the frangible web canalso be opened locally, and the deburring station includes a separatingroller pair that separates the wire conductor ribbon into wireconductors, the object of the invention furthermore being achieved by aspreading roller unit in which even-numbered wire conductors are spreadapart relative to uneven-numbered wire conductors such that two arraysof mutually spaced wire conductors are created, furthermore onedeburring device for each of the two arrays of wire conductors, as wellas rollers forming a drawing unit in which the wire conductors arereunited into a common group.

The deburring device here advantageously includes tines arranged as in acomb and forming deburring cutters.

Another advantageous aspect is that the deburring device is oriented atan acute angle to the travel direction of the wire conductors so as toreinforce the self-alignment effect of the wire conductors since thecutting width is increased, and also to ensure is downward ejection ofchips.

Regardless of the angle between the wire conductors and the deburringdevice that is specifically selected or set in terms of the operation,what has been found advantageous for this purpose is a value ofapproximately 45.

Provision is furthermore made within the scope of the invention wherebythe deburring device is adjustable longitudinally of the tines. Thisallows the deburring device to be reset if the cutters have become dullin the working area.

In order finally to be able to feed the separated wire conductors to thedeburring device in an ordered arrangement and alignment, it can beadvantageous for the rollers of the spreading unit to be provided withguide grooves for the wire conductors. The deburring device should beplaced centrally between the spreading rollers and the drawing unit; theselected spacing here from the spreading rollers to the drawing unitmust be sufficiently great to allow the wire conductors to be easilyaligned automatically in the horizontal plane according to the cuttingpressure.

The following describes the invention in more detail with reference topan embodiment illustrated in the drawing in which:

FIG. 1 is a schematic side view of an apparatus for carrying out themethod according to the invention;

FIG. 2 is a view of the deburring device in the direction of production;

FIG. 3 is a side view of the structure shown in FIG. 2;

FIG. 4 is a detail in cross-section from FIG. 2.

The arrangement shown in FIG. 1 deburrs wire conductors 1 that have beenseparated out from a wire-conductor ribbon 2 comprising a plurality ofparallel wire conductors. This deburring method is intended inparticular for producing round and/or profiled wires.

In order to form the wire conductors 1 from the wire conductor ribbon 2fed to this illustrated arrangement, a metal sheet is first pregroovedon one or both faces to form wire conductors 1 that are connected bywebs after grooving, then undergo a flexing process such that the websare transformed into thin frangible webs that are easily separable fromeach other to form smooth and nearly burr-free edges. During thisflexing process, each web undergoes repeated bending deformation aboutits longitudinal axis such that incipient cracks are formed by fatiguefailure in the webs to convert them into the frangible web that can beopened locally.

In the arrangement of FIG. 1, this thus created wire conductor ribbon 2first passes through a separating roller pair 3 that separates wireconductors 1 that are still connected to each other by frangible webs orresidual frangible webs. A roller unit 4 positioned downstream of theseparating roller pair 3 spreads the now separated wire conductors 1 aseven-numbered and uneven-numbered wire conductors such that two arraysof spaced wire conductors 1 are formed. Since each of the two arrays nowcontains every second wire conductor from the original wire conductorribbon 2, the result is that gaps, which each have approximately thewidth of a wire conductor 1 that is actually in the other group, arecreated between adjacent wire conductors 1 in each group.

These two arrays of wire conductors 1 then each pass through a deburringdevice 5 and are then reunited into a common group of wire conductors 1between rollers of a drawing unit 6.

As is evident in particular in FIG. 2, the two deburring devices 5 areformed as combs having tines 6 whose edge faces form cutters for thedeburring operation.

The wire conductors 1 are transported through the deburring stationunder tension, the drawing unit 6 generating the draw force alsorequired to advance these wire conductors 1 while the separating rollers3 and spreading rollers 4 generate a braking force, with the result thatthe requisite draw tension is created by the interaction of thesedevices that vertically orient the wire conductors 1 upstream of thedeburring device 5 as a result of to resting gently on a horizontallydisposed guide roller 7. The guide roller 7 furthermore suppressesvibration in the wire conductors 1.

Relative to their horizontal axes, the wire conductors 1 adjustthemselves automatically for a uniform two-sided deburring operationsince—due to the angles of the groove flanks—the cutting width that isset on both sides of wire conductor 1 by the cutting pressure isapproximately equal, and the wire conductor is thus aligned centrallyrelative to the cutters of the deburring device. This self-alignment ismost effective given a width/thickness ratio of 1:1, that is, when thewidth of the wire conductor is not too great.

Since refeeding of a new wire conductor ribbon 2 is laborious due to therequired spreading of individual wire conductors 1, it is recommendedthat the process be operated using “endless” wire conductor ribbons 2.To this end, a welding station can be provided upstream of theseparating roller pair 3, at which station the start of a new wireconductor ribbon 2 can be butt-welded on so that individual wireconductors 1 are aligned flush with each other. The welding bead formedhere on the welding seam can then be ground flat on both edges of theconductor ribbon 2 using a method not shown in detail in the drawing,and the welding bead can also be removed at the grooves so as to ensurethat subsequently at the welding seam it is also possible to separatewire conductors 1 from each other without difficulty.

As FIG. 3 shows, the tines 6 together with the cutters of deburringdevice 5 are oriented at an acute angle to the travel direction of thewire conductors 1 so that the cut line is somewhat increased, and thecutting pressure effected by the self-alignment of the wire conductorsis thereby also increased, while the chips accumulated during deburringare also directed downward. In addition, the deburring device 5 isadjustable longitudinally of the tines 6, thereby allowing forreadjustment whenever the cutters formed by the tines are dull in theworking region.

1. A method for simultaneously deburring a multiplicity of wireconductors separated from a wire conductor ribbon and parallel to eachother for producing round and shaped wires, wherein a sheet metal ribbonis first pregrooved on one or both sides so as to create the wireconductors of the wire conductor ribbon, after which the wire conductorsstill connected after grooving by webs undergo a flexing process so asto convert the webs into thin frangible webs that are easily separablefrom each other and that form smooth and nearly burr-free edges whendetached, each web undergoing repeated bending deformation about itslongitudinal axis in such a way that incipient cracks forming thefrangible web are created by fatigue failure at the webs, wherein thefrangible web can also be opened locally, characterized in that the wireconductors, after passing through a separating roller pair, are spreadapart according to even-numbered and odd-numbered wire conductors by aspreading roller unit such that two arrays of relatively spaced wireconductors are created, wherein furthermore the two arrays of wireconductors pass under adjustable tension through respective deburringstations provided with respective deburring cutters, the draw tensionbeing selected such that an automatic, central alignment, and thus atwo-sided uniform removal of chips, is effected on the wire conductorsdue to the action of the groove-flank angle and of the adjusted angle ofthe deburring cutters, and wherein finally the wire conductors arereunited into a common group of wire conductors by rollers of a drawingunit.
 2. The method according to claim 1, wherein the deburring stationincludes a comb-like deburring device that is provided with tines thatform the deburring cutters.
 3. The method according to claims 1 whereinthe drawing unit downstream of the deburring station generates the drawtension intended for deburring as well as the draw force required toadvance the wire conductors, and the separating roller pair and thespreading roller unit generate an opposing braking force, and both unitsare provided with guide grooves for the wire conductors.
 4. The methodaccording to claim 1 wherein the wire conductors are not subjected torestricted guidance in the horizontal plane so as to provide a uniform,two-sided deburring operation in the region upstream and downstream ofthe deburring station.
 5. The method according to claim 1 wherein thewire conductors are guided vertically upstream of each of the deburringdevices only under light applied pressure across one respective smoothguide roller.
 6. The method according to claim 1 wherein the conductorribbon passes through a welding station before entering the separatingroller pair, in which station a new conductor ribbon is welded on whenthe end of a conductor ribbon has been reached such that the individualwire conductors are flush with each other.
 7. The method according toclaim 6, wherein the welding bead formed on the welding seam is groundflat on both sides of the conductor ribbon, and the welding bead at thegrooves is also almost completely removed by an appropriately shapedtool by bilaterally and simultaneously grinding the top side and bottomside of the conductor ribbon.
 8. An apparatus for carrying out themethod according to claim 1, comprising: a deburring station for aconductor ribbon that is formed from a metal sheet in which wireconductors still connected by webs after grooving undergo a flexingprocess so as to then transform the webs into thin frangible webs thatare easily separable from each other and form smooth and nearlyburr-free edges when detached, whereby, after undergoing repeatedbending deformation about their longitudinal axis, incipient cracksforming the frangible webs are created by fatigue failure at the webs,which frangible web can also be opened locally, wherein the deburringstation includes a separating roller pair that separates the wireconductor ribbon into wire conductors, furthermore by a spreading rollerunit in which even-numbered wire conductors are spread apart relative touneven-numbered wire conductors such that two arrays of mutually spacedwire conductors are created, furthermore by a respective deburringdevice for each of the two arrays of wire conductors, as well as rollersforming a drawing unit in which the wire conductors are reunited into acommon group, so that approximately the same tension acts on all wireconductors.
 9. The apparatus according to claim 8, wherein the deburringdevice includes tines arranged like in a comb and forming deburringcutters.
 10. The apparatus according to claim 9, wherein the tines areoriented at an acute angle to the travel direction of the wireconductors.
 11. The apparatus according to claim 9 wherein the tines areoriented at an angle of approximately 45° to the wire conductors. 12.The apparatus according to claim 9 wherein the deburring device isadjustable in the longitudinal direction of the tines.
 13. The apparatusaccording to claim 9 wherein the rollers of the spreading roller unitand the drawing unit are provided with guide grooves for the wireconductors.